Abstract:

The effect of 10 μM Cd²⁺ on 20 tall fescue varieties were investigated using water culture method. Cadmium resistance and accumulation characteristics were evaluated comprehensively by employing the method of subordinate function and clustering analysis. The results showed that the Cd²⁺ stress had significant effects on plant height, root length, biomass, and the photosynthetic pigment content of tall fescue. The variations of the different varieties reached significant level (P<0.05). Average subordinate function values for 20 varieties ranged 0.185 to 0.758, and the cadmium tolerate of ‘Commander’ was the strongest. The cadmium absorption and accumulation were significantly different among 20 varieties with the Cd²⁺ content of shoot from 106.66 to 150.97 mg·kg^-1. Cd²⁺ accumulation reached the maximum of 6.87 μg·plant^-1, and the minimum was 2.75 μg·plant^-1.Based on Cd²⁺ absorption and accumulation, ‘Commander’ and ‘Red Start’ were better than the others. According to the result of comprehensive evaluation, the 20 tall fescue varieties were divided into 4 types, high-tolerance and high-accumulation: ‘Arid 3’, ‘Extreme’, ‘Commander’, ‘Escalade’, ‘Ecological King’, ‘Ky-32’, ‘Red Start’, ‘Green Label’; high-tolerance and low-accumulation: ‘Gold Crown’, ‘Justice’, ‘Honky Tonk’, ‘Aries’; low-tolerance and high-accumulation: ‘RubyⅡ’, ‘Coronado TDH’; low-tolerance and low-accumulation: ‘K31’, ‘Crossfire III’, ‘Essential’, ‘Super Watchdog’, ‘Gram villa’, ‘Dynamic II’.

Key words: Tall fescue, Cd²⁺, Tolerance, Accumulation characteristics, Subordinate function values analysis

摘要：

采用水培试验，用10 μM Cd²⁺对20个高羊茅（Festuca arundinacea）品种进行处理，采用隶属函数值法和聚类分析法对其镉耐性和富集特征进行综合评价。结果表明，与对照相比，Cd²⁺处理下所有参试高羊茅品种在株高、根长、生物量和光合色素含量等指标上均显著降低（P<0.05），品种间变化值的差异也达到了显著水平（P<0.05）。20份材料的平均隶属函数值变幅在为0.185~0.758，其中‘Commander’的镉耐性最强。20个品种间Cd²⁺吸收和累积量也有很大差异，地上部Cd²⁺浓度范围为106.66~150.97 mg·kg^-1，Cd²⁺累积量最高值为6.87 μg·株^-1，最低值仅2.75 μg·株^-1，其中品种‘Commander’和‘Red Start’在Cd²⁺吸收和累积上表现较好。通过综合评价最终将20个高羊茅品种分为4类，分别是高耐高吸收型：‘Arid 3’，‘Extreme’，‘Commander’，‘Escalade’，‘Ecological King’，‘Ky-32’，‘Red Start’，‘Green Label’；高耐低吸收型：‘Gold Crown’，‘Justice’，‘Honky Tonk’，‘Aries’；低耐高吸收型：‘RubyⅡ’，‘Coronado TDH’；低耐低吸收型：‘K31’，‘Crossfire III’，‘Essential’，‘Super Watchdog’，‘Gram villa’，‘Dynamic II’。

关键词: 高羊茅, Cd²⁺, 耐受性, 富集特征, 隶属函数法